Thermoacoustic, how?

[bidouille23]

Good evening,

here is a document with a very nice and cheap essay at the bottom of the page .

http://thermoacoustique.free.fr/effetth ... stique.htm

a recovery of catalytic converters is essential .

see you

[dedeleco]

It's cute but I put on econology full of links on the same subject especially the same system on wikipedia and many more scientific articles.
This post does not give the wikipedia references on the length of diffusion in the air by laying the formula without clear explanations length of thermal diffusion = 4mmxracine (time in s) in the air, 4 with 10 times more than in the earth for Summer thermal storage to winter!
It would be good to copy here all these links already given much more documented !!
hack would do well to read them because the shape of the tube with amplifier effect by cone expansion flag is important for the performance.
We can take anything from finely divided metal, like iron or nickel straw instead of Pt, like stack.
The pressure is important to increase the power.
There are lots of Stirling videos with a stack.

I think that with steam in addition to a condensable gas (water, acetone, etc. ..) we must increase efficiency by doing well!
Indeed we would turn it into a thermoacoustic steam engine !!
The pressure and volume variations are much higher with condensation and evaporation and therefore the effect must be more powerful.
We can even make a Wilson room to see the radioactive radiation!
But I did not see anyone talk about it or imagine it !!

There are systems with thermoacoustic motor coupled with thermoacoustic refrigerator on the same tube !!
It is cold with the heat of a stove without moving parts.

With solar heat, thermoacoustics can be more efficient than photovoltaic !!

Look at all the links on econology, because I'm tired of repeating myself.

[bidouille23]

Hello ,

Dedelco it's a good idea to bring together all the links on the thermoacoustic engine.

I read that for the most physicist that I can also talk more;), especially about the stack;)

http://cfa.sfa.asso.fr/cd1/data/articles/000033.pdf

Indeed it lacks full explanations in the first link but not seeing the links you gave before Dedelco when I saw this simple experience and I found it nice to do a simple test and cheap c is everything, and rather amusing and surprising.

Actually when talking about sound, reused the amplification technique by flag seems all makes logical yes mm.

“Pressure is important to increase power.
There are plenty of Stirling videos with a stack "
I think that with a car catalyst you will have much more pressure than with iron straw, I'm wrong?

Let go Dedelco gathers;) it can only be good.

see you

[dedeleco]

It is a field in full research, with a lot of studies, achievements and expansion.
This article is interesting, but for a realization very studied thoroughly and powerful.

An example of thermoacoustic solar tile:
http://www.io.com/~frg/tar.htm

This site to read !!

with a car catalyst you will have much more pressure than with iron straw, I'm wrong?

what counts is a good heat exchange (distance between walls lower than the diffusion length at the operating frequency) and the easy passage of gas as much as possible.
So the catalytic converter responds to that but it is very harmful (to clean thoroughly as explained on another page of the link you gave), but any finely divided metal with easy air passages narrower than the length diffusion is suitable (around 0,4mm max to 100 Hertz).
On the videos there are some of iron or copper.
It sounds easy for a low yield, but difficult for the optimum and full of patents.

I put these links on:

https://www.econologie.com/forums/post175140.html#175140

I find very attractive Stirling thermoacoustic capable of refrigeration, and without any moving parts or piston!!
http://thermoacoustique.free.fr/
http://fr.wikipedia.org/wiki/Thermoacoustique
http://en.wikipedia.org/wiki/Thermoacou ... air_engine
http://www.stirlingengines.org.uk/thermo/thermoc.html
http://www.lanl.gov/projects/thermoacou ... index.html
http://www.videosurf.com/video/lamina-f ... ?vlt=ffext
http://www.videosurf.com/video/solar-po ... ?vlt=ffext
http://www.lanl.gov/thermoacoustics/Pub ... cwLAUR.pdf
http://www.projetstirling.fr/index.php? ... &Itemid=28
http://www.acs.psu.edu/thermoacoustics/
http://www.io.com/~frg/
http://www.io.com/~frg/history.htm
In my opinion its potential is immense, it is used for refrigerators of liquid gas, without any compressor and even with liquid nitrogen.

And hack did not react after, focused on antiquity Phillips not found!

[bidouille23]

Hello Dedelco,

I had already read the site on the mems-tar, I find it fantastic too, not being able to have a realistic critical eye I do not know what to think. I'm going to say that I cross and that I 'wait for the production of such a system with envy if can say .

I will read the other links thanks old biker than ever;).


"And hack had not reacted afterwards, focused on the antique Phillips not found !!!"
1) you can tu tu tu;)
2) quite often times have blinkers that are put like big ones

3) does not prevent I'm sure now that this philips engine was a thermoacoustic engine No, I'm not stubborn lol
and that's the big brother of the current refrigerator motor;).

Well, there's more to read it's good true

see you

[bleusideral]

Hello
I read this subject with passion and I too find it great, I hope that one day it will be develloped industrially and replace all the ancestral systems of energy and gas-consuming compressors, but the battle will certainly be difficult considering the implication already in place of the current system of industrial ...
the future of air conditioning would be affected too !?

[chatelot16]

I still do not see an example of thermoacoustic stirling producing really mechanical or electrical power: it's mostly noise

the conversion of sound into electricity has a very poor performance with a simple speaker not resonant

to make a better performance it takes a resonant system ... except that the thermoacoustics is the frequency it wants according to the temperature of the gases in its pipes: it is therefore necessary a resonance frequency of the super loudspeaker tunable automatically permanently

I'm even afraid that there is a need for variable length in the different parts of the system, to get a good operation

the problem is not the same for the thermoacoustics in the refrigerating machine: it is used in cases where the compressor system is difficult to achieve: very low temperature: in this case the simplicity of the thermoacoustic is aprecie even if its performance is bad

to return to the stirling engine, I do not see any advantage to thermoacoustics: the thermoacoustic part may be simple, the transformation part of the sound into electricity seems too difficult

at least with the real stirling the piston part is classic

[dedeleco]

This reaction corresponds to knowledge that is that of classical Stirling, but not to recent thermoacoustics, which requires more knowledge on waves, impedance adaptations, etc., very essential, and used in scientific and industrial achievements. pointed, quite secretive, given their real potential, even military or space.
It is necessary to read the scientific publications that google and google scholar gives and even to see videos of big machines, often cryogenic with double thermoacoustic, motor and refrigerator, before having a final definite opinion.

I give again very partial references:
Watch my links given on this forum and others econology, all coming from wikipedia and google for thermoacoustic and Stirling, which give a thousand links and scientific articles and patents very serious, with simple and complex videos!

http://fr.wikipedia.org/wiki/Thermoacoustique
http://thermoacoustic.free.fr/
http://en.wikipedia.org/wiki/Thermoacoustic_heat_engine

A class :
http://www.sft.asso.fr/Local/sft/dir/us ... stique.pdf

http://www.prismnet.com/~frg/
http://www.projetstirling.fr/index.php? ... &Itemid=28
http://peswiki.com/index.php/Directory: ... _Generator

videos:
http://www.youtube.com/watch?v=4YKWeMw0TCc
http://www.youtube.com/watch?v=GNGCOmua ... re=related
http://www.youtube.com/watch?v=PcyRZlIvBUU
http://www.youtube.com/watch?v=V-fKHf4MjnM
http://pubs.acs.org/doi/abs/10.1021/nn200338r

the number of achievements quickly grows:
http://www.google.fr/search?q=thermoaco ... =firefox-a

http://www.google.fr/search?num=100&hl= ... 1.7.3l11l0

[chatelot16]

instead of always repeating the same link, give us some ideas about the conversion of sound into energy: I still do not see anything precise

but I will end up finding ideas by a way diverted

I already have some resonator home who work well: pot resonator echpement on motorcycle 50cm3

I wanted to make a sliding resonator for a long time to adapt it to the rotation speed of the motor

your acoustic stirling give me the idea to add a stack in the resonator to use the heat of exhaust with a stirling effect ... even if the performance is not huge it will always be a little more .. and then I leave the muffler alone, and I simply note that a large, long resonator may have a frequency low enough to be compatible with a good old piston engine.

the problem of the speaker is classified: just make the thermoacoustic stirling long enough to fall on a low enough frequency for a piston

it will make a stirling more cumbersome than the conventional system with displacer ... but it's a try anyway

with the stirling has displacer, it is necessary to optimize the mechanics to minimize the dead space: if I put more small cylinder and displacer, it is also necessary of as much of piston engine: to channel everything towards a single engine cylinder would make too much volume dead

with the thermoacoustics there is no dead volume there are only large tubes that have the right length to resone well: there is no problem to put small tube level stack and exchanger, and put a single receiver piston of the sound wave

comparison: the classic stirling is fully mechanical, and runs at any speed

the thermoacoustic stirling will have to be electronically controlled to adapt the speed of rotation to the frequency of resonance

[chatelot16]

videos:
http://www.youtube.com/watch?v=4YKWeMw0TCc

do not confuse anything with thermoacoustics

we see on youtube a bunch of small engine called lamina flow engine: it's not thermoacoustics

with such short tube it makes a resonator at acute frequency which can not be followed by any piston or crankshaft

I understand these engine as stirling or the displacer is replaced by a delay in the stainless steel straw

it's not methodical at all: no hope for good performance: these little things are running just empty, unlike small stirling has the same size that can cause something